1. Field of Invention
The present invention relates to an earphone structure. More particularly, the present invention relates to an ergonomically designed earphone structure for human ear.
2. Description of Related Art
Personal audio systems are popular everywhere these days. Audio systems can provide users various kinds of entertainment while they are engaged in all sorts of activities. People can listen to radio broadcasting, cassette tapes or optical disk any time they want. The most common type of audio system has stereo earphones for both ears or a single earphone for just one ear. In general, the earphone is attached to the human ear so that a user can listen to the sound produced by the system without disturbing others. One further advantage of listening with an earphone is the good quality of sound that can be provided to its user. The user is able to receive clear sound or voice signals with very little background noise as cannot be done with any sound system that transmits sound through the air. Hence, listening can still be carried on even when a user is exercising or engaged in activities in a noisy environment. In addition, earphones are often used in an environment that involves two-way communication such as lecturing, or telephone and wireless communication. In fact, when two-way communication is required, a microphone is usually attached to the earphone and extended towards user's mouth so that communication can carry on without using either hand.
FIGS. 1A and 1B are sketches showing the respective front and back portions of a conventional earphone-microphone set having just a single ear brace. As shown in FIGS. 1A and 1B, the earphone-microphone set 100 includes an earphone body 102, an ear brace 104, a microphone 106, a signal transmission cable 108 and a plug 110. The ends of ear brace 104 are inserted into holes 102a and 102b of the earphone body 102 such that the ear brace 104 can rotate about earphone body 102. The ear brace 104 has a roughly triangular shape specially designed for mounting onto a user's ear. In general, the ear brace 104 is made from some hard plastic material. A microphone 106 is also attached to the earphone body 102. The microphone 106 is attached in such a way that rotation of the microphone 106 relative to the earphone body 102 is possible.
As shown in FIG. 1A the tip of the microphone is able to sweep out an angle .PHI. upward or downward with respect to the central line Z. Hence, the microphone 106 can be adjusted to a level that fits the talking position of the user no matter if the earphone set is worn on the left or the right ear. The signal transmission cable 108 comes out through the earphone body 102 near position B.
In summary, the ear brace structure of a conventional earphone-microphone set is usually worn around the periphery of the ear. Since the ear brace is usually formed from hard plastic material, the user may feel discomfort after wearing the earphone for a while because the human ear is a soft and fleshy organ.
Furthermore, a conventional ear brace has a fixed triangular structure. Therefore, the ear brace can hardly match the shape of each individual ear. For example, when the user's ear is big, the ear has to be squeezed into the ear brace. On the other hand, if the user's ear is small, the ear brace can barely grip the ear at all, and the earphone can easily slip off the ear.
In addition, the signal transmission cable of a convention earphone system normally comes out horizontally near the edge of the earphone body. Consequently, when the signal line is accidentally pulled, the earphone can easily come off, causing great inconvenience to the user.
In light of the foregoing, there is a need to provide an earphone-microphone set that has a pair of adjustable ear braces.